Star Lecture

March 20, 2004

Over 70 people from the Society, and other Friends of the NMM, were treated to an enthralling presentation by David Sellers on the science and drama of the Transits of Venus and expeditions to get accurate measurements of these very rare events (see our Transit of Venus page for more information and links to helpful websites).   David spoke with comprehensive authority, passion, and humour, and illustrated his talk with clear and entertaining slides.   His lecture was followed by 30 minutes of very varied questions and an impromptu book signing (which almost deprived David of his guided tour of some of the NMM’s James Cook exhibits - although a cup of tea would probably have been very welcome by then, too!)

David Sellers is a committee member of the Leeds Astronomical Society, and Editor of their “Nebula” magazine


David Sellers:  “The Transit of Venus—The Quest to Find the True Distance of the Sun”

David, Linn Potter (Flamsteed Chair), and Eddie Yeadon

“The Transit of Venus” is David’s first full-length book, although he has previous publications covering sundials in Leeds, and the history of the Leeds sewerage system (a professional interest).    David’s astronomy interests are positional astronomy and the history of the science.

The lecture featured the history of observation of the Transit beginning with Jeremiah Horrocks and William Crabtree, who recorded the 1639 transit (an event not predicted by Kepler). Horrocks’ calculations, based on little data, produced a very respectable figure for the distance from the Earth to the Sun and multiplied four-fold the then understood size of the solar system. 

David entertained the audience with graphic tales of the personal sacrifices of the 18th Century astronomers who travelled far afield to measure the 1761 and 1769 transits.  In particular, some astronomers gave up a decade of their lives to try and be in the right place for the event.   Two astronomers gave their lives to disease after travelling to the tropics to make the measurements.

The impromptu book signing was very popular and over-subscribed

Many thanks also, to Colin, John, and Eddie who conducted the audience around the Cook exhibits after the talk.  Not to forget Jane, Linn, and Nicki who did the hard work of organising and running the event.

Jane attempts to get things back on time